diff --git a/boot_control_interface.h b/boot_control_interface.h
new file mode 100644
index 0000000..135d2eb
--- /dev/null
+++ b/boot_control_interface.h
@@ -0,0 +1,85 @@
+//
+// Copyright (C) 2015 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+#ifndef UPDATE_ENGINE_BOOT_CONTROL_INTERFACE_H_
+#define UPDATE_ENGINE_BOOT_CONTROL_INTERFACE_H_
+
+#include <climits>
+#include <string>
+
+#include <base/macros.h>
+
+namespace chromeos_update_engine {
+
+// The abstract boot control interface defines the interaction with the
+// platform's bootloader hiding vendor-specific details from the rest of
+// update_engine. This interface is used for controlling where the device should
+// boot from.
+class BootControlInterface {
+ public:
+  using Slot = unsigned int;
+
+  static const Slot kInvalidSlot = UINT_MAX;
+
+  virtual ~BootControlInterface() = default;
+
+  // Return the number of update slots in the system. A system will normally
+  // have two slots, named "A" and "B" in the documentation, but sometimes
+  // images running from other media can have only one slot, like some USB
+  // image. Systems with only one slot won't be able to update.
+  virtual unsigned int GetNumSlots() const = 0;
+
+  // Return the slot where we are running the system from. On success, the
+  // result is a number between 0 and GetNumSlots() - 1. Otherwise, log an error
+  // and return kInvalidSlot.
+  virtual Slot GetCurrentSlot() const = 0;
+
+  // Determines the block device for the given partition name and slot number.
+  // The |slot| number must be between 0 and GetNumSlots() - 1 and the
+  // |partition_name| is a platform-specific name that identifies a partition on
+  // every slot. On success, returns true and stores the block device in
+  // |device|.
+  virtual bool GetPartitionDevice(const std::string& partition_name,
+                                  Slot slot,
+                                  std::string* device) const = 0;
+
+  // Returns whether the passed |slot| is marked as bootable. Returns false if
+  // the slot is invalid.
+  virtual bool IsSlotBootable(Slot slot) const = 0;
+
+  // Mark the specified slot unbootable. No other slot flags are modified.
+  // Returns true on success.
+  virtual bool MarkSlotUnbootable(Slot slot) = 0;
+
+  // Return a human-readable slot name used for logging.
+  static std::string SlotName(Slot slot) {
+    if (slot == kInvalidSlot)
+      return "INVALID";
+    if (slot < 26)
+      return std::string(1, 'A' + slot);
+    return "TOO_BIG";
+  }
+
+ protected:
+  BootControlInterface() = default;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(BootControlInterface);
+};
+
+}  // namespace chromeos_update_engine
+
+#endif  // UPDATE_ENGINE_BOOT_CONTROL_INTERFACE_H_